Portable hoist



June 19, 1945. c, E. WATSON 2,378,505

, yPORTABLE HoIsT Filed Feb. 7, 1942 5 Sheets-*Sheei'I 2 lNvE/vroR.

FI .4. CHARLES-E. ArsoN.-

G BYa/W] C; B?

ATTORNEY.

C. E. WATSON PORTABLE. HoIsT Filed Feb. 7, 1942 June 19, 1945.v

5 Sheets-.Sheet 3 l/vvENTOR.

CHARLES E. WATSON.

June 19, 1945. c. E/wATsoN PORTABLE HoIsT Filed Febp?. 1942 5 Sheets-Sheet 4 ITI-14.

INVENTOR.

CHARLES E. WATSON Y @L c ATTORNEY.,

June l9\ 1945 c. E. wA'rsoN PORTABLE HoIsT Filed Feb. 7, 1942 5 Sheets-sheet s 0 6 v mi, 2 l 3 E :NVE/won.

ATTORNEY.

Patented June 19, 1945 PORTABLE HoIsT lCharles. E. Watson, Chicago, 111 assignor. to Bird- Whte Corporation, Chicago, `Ill., a corporation of Illinois Application'February 7, 19.42, Serial No. v429,921'` Q9 cremisi, (c1. 25er-139.1)

This invention relates 'to portable hoistsl` and more particularly to hoists offsectional construe'- tion, although certain features thereof may be employed with equal advantage for other pur- Doses. Y f

vIt contemplates more especially the provision of a sectional hoist of the portable type which may be readily assembled and dismantled for rendering such equipment 'readily transportable tol distant locations Without entailing any appreciable labor,.time or expense.v

Hoists are essential service equipment in conjunction With vehicles such as airplanes in that there is a Lvariety of hoisting problems in the cleansing, servicing and 'replacementj'of parts. Y

In the servicing of large vehicles such as airplanes it isnot practical to have fully equipped stationary service shops at al1 airports or'hangars at Which the airplanes may be readily landed,

housed, or r'repair service may7 be required forV routine or emergency" purposes. Airplanes are becoming increasingly large structural bodies or units and 'service equipment mustnecessarily be brought to such huge units that are to be serviced.

This physicalI limitation coupled with the re;-

Vquirernent for complete mobilityv in reiecting the hoists or similar maintenance-equipment are not 3 usually available in suillcient' numbersA to provide all servicing stations or airfields v therewith'so that even underordinary conditions of maintenance, it may become necessary totransport such heavy equipment Yto the service requirements of widespread geographic locations.

Airplanes are also putout of service or restorative repair andk replacement must be'made at points of forced landing so that complete moybility of heavy maintenance equipment such as hoists, is anextremely advantageous structural feature. To meet such unusual requirements, it

is proposed to provide heavy servicing equipment of sectional construction so that they may be dismantled and transported by airplane or other suitable transportation mediums to the situs of such service requirements and there assembled as readily as dismantled. Ivvnile.. portable holsts have long been available, yet the requirement` for knownv construction not entirely satisfactory from that standpoint. y

To this end,l the present invention eliminates the comparative immobility of such equipment by providing a sectional lconstruction of self-contained units that are readily assembled and dismantled to meet varyingand-repeated changes in the situs requirements therefor.. To this end, the dismantledsections are readily placed in the vehicle such as an airplane for delivery'toany needed point of use.- This accomplishment coupled with the features of rendering such readily assembled andY dismantled Without;k impairment by the stresses yand strainsthat are to be carriedby'the parts, is rendered possible with the teachings of the present inventionrv One object of the present invention is to simplify the constructionl and improve the operation of devices of thefcharacter mentioned.

Another object is to provide a structural'body comprising self-contained sections that are readily assembled and dismantled to comprise a selfcontained hoistfor. convenience in transporting to different situs requirements.

Still another object is to provide a plurality of self-contained telescopic units that are readily assembled yand dismantled to comprise a self-contained hoist for? convenience in transporting to different situs requirements.

"A further object 'is to'provide self-contained truss rod'telescopic units to comprise a portable hoist for ready assembling and dismantling to meet different situs requirements.

' A lstill further object is to provide a sectional hoist of improved construction.

Still a further object is to provide vertical and angularly disposable self-contained truss rod units to comprise va telescopically assembled sectional hoist or the like. l

Other objects and advantages will appear from the following description and illustrated embodiment of the present invention.

In the drawings:r Figure 1 is'a side view in elevation of a sectional hoist embodying features of the present invention. y f

" Figure 2 is an enlarged fragmentary sectional Y View taken substantially along line 11-11 of Figure 1.. l

Figure 3 is a plan vievv of the device shown in Figure 1. j

Figure 4' is an enlarged' fragmentary sectional view takensubstantially along line IV-IV of Figtheir availability at the situs of repair renders ure 3.

Figure 5 is an enlarged fragmentary sectional view of the front axle construction.

Figure 6 is a perspective view of the boom section of the hoist structure.

Figure 7 is an enlarged fragmentary sectional detail view of the rear boom connection.

Figure 8 is an enlarged fragmentary sectional View of the lowerboom pivot or section `connec tion rod.

Figure 9 is a perspective detail view of the hoist base, parts thereof being broken 'away to clarify,

the showing.

Figure 10 is a front view in elevation of the vertical column section.

Figure 11 is a plan view of the vertical column section shown in Figure 10.

Figure 12 is an enlarged fragmentary view of ,thereof being broken away and sectioned to clarify the showing.

Figure 15 is a perspective detail view of one of the truss-rod leg sections.`

Figure 16 is a front detail view in elevation of a leg cross-tie member or unit.

Figure 17 is an enlarged fragmentary detail view of the leg cross-tie member connection.`

Figure 18 is an enlarged detail view of a front steering wheel assembly.

' Figure 19 is a sectional view taken substantially along line XIX- XIX of Figure 18.

'I'he structure selected for illustration comprises a handle member Ill consisting kof a terminal cross-bar I I to enable manual grasp thereof in exerting a pull and steering influence upon an elongated tubular hand rod I 2. The elongated tubular rod I2 terminates in a transverse collar cable to the other.

I3 welded or otherwise attached thereto dependl ing upon the dictates of commerciall practice. The collar I3 receives a carriage Ibolt I4 :axially therethrough to bridge space plates I5v-I'5 (Fig- I ure 3) constitutinga part of a .double wheel castor bracket I1 (Figures 1 and 18). Closely spaced double wheels I8--I9 are journalled on the castor bracket I1 that pivots in a horizontal plane for steering purposes. The Wheel mounting castor bracket I1 has a vertically lextending stud 20 which is ljournalled in the vertical tubular bearing 2| constituting a part of the base assembly section 22. The castor mounting bracket I1 has an .axle I1' to vertically pivot stub `shafts I 8-I9' on which wheels I8 and I9 are journalled.

The base assembly 22 consists, in this instance,

of truss rods which are designed to withstand stantially triangular base frame 22.v The triangular section of the base frame 22 has upper and lower converging struts 26--21 and 26-21 (Figure 9) that are joined with the vertical ,forward rod and .diverging .struts 23-24 through the medium of welded tubular socket brackets 28--29 to enable their effective welded j oinder. The triangular section of the base frame 22 is defined by superposed truss rods 30--3I that are joined through corner socket brackets 32--33 and 311-35 to connect the base rods 30--3I to the triangularly disposed divergent rods 26--26 and 21-21' to define a triangular base section having forwardly extending brace rods 23--24 serving as a support for the vertical bearing sleeve 2I.

In order to rigidify the triangular base frame 22 and increase the carrying load thereof, intersecting diagonal truss rod braces 35, 31 and 323 are welded or otherwise joined to the upper and lower diverging side and triangle forming base rods 26, 2624-30 and 21, 21-3I of the base section 22. It should be noted that vertical rods 3,9 and complete the triangular sides and base to serve as .a base for both triangular frames 26--21 and the substantially. rectangular frame base 3Il-3I. Auxiliary side rods 4I-42 converge at the vertical bearing sleeve 2l for welded joinder therewith so that the other extremities thereof will merge 'with the Welded tubular socket brackets 43--44 constituting the intersecting medium for the side triangular frame braces 36-31. Thus a rigid self-contained frame base section 22 is provided for forward support by the .wheels `IIS-I9 mounted on the castor brackets The base frame section 22 issupported rearwardly by converging leg sections 45 and 46 which constitute self-contained units adapted for telescopic association with the base frame 224 as will presently appear. While the leg sections I5- 4S are of opposite inclination to comprise a left and right section, other than for this change in inclination the structural features of each are identical so that a description of one is equally appli It should be observed that the leg sections 45--46 comprise in this instance a horizontally disposed lower rod 41 having an inclined rod 4,8 in superposed relation therewith for intersecting engagement at their rearward extremities 49--50 which are complements of al socket bracket 5I to which the rod extremities 49-50 are welded or otherwise permanently joined. The forward extremities of the rods 41-48 are inter-connected or braced by means ofla strut 52 which completes a triangular section by being joined thereto through the medium of corner rod socket brackets 53-54 Intermediate the apex 5| and the base 52 of the triangular sections 45-46, a vertical reinforcing strut 55 is provided to comprise a brace intermediate the ends thereof. 1

To this end, the bracing strut 55 is joined to rod socket brackets 56--51 that envelop the rods 41-48 for permanent attachment thereto in the plane of the triangular section 41-48-52. Lateral bracing of each leg section 45-45 is effected by converging rodsl 58-59 anchored to the corner socket brackets 53-54 as at Ell-5I with their other extremities (i2-63 converging with a vertical brace rod `64 (Figurerl) which is welded or otherwise joined thereto.

The vertical brace rod `64 is spaced laterally from and supported by the vertical strut 55 through the `medium of vertically spaced horizontal tube braces 65-66, the latter being welded to the brace rod 54 and the strut 55. The tubular brace rod 64 has a pin 61 extending vertically .therethrough to engage the lower and upper vertical bearings 68-69 comprising portions of socketbrackets 1li-1I, respectively. These are maintained and spaced in vertical relation to correspond with the length of the vertical brace rod 64 by means of vertical spacer rods 12 provided (Figure at both extremities of a cross-tie member 13 (Figure 16). The cross-tie membe'r13 comprises a lower horizontal rod 14 yand intersecting -angularrods 'l5-1B that are welded thereto as at Tlintermediatethe extremities of the horizontal rod 14. The other extremities of the converging rods Hi-16 are welded or otherwise anchored to the upper socket bracket 'H to maintain the lower and upper Vertical bearings 68-69 in vertical axial alignment. As a result, the leg units -46` are maintained in spaced relation by means of the connecting tie memberrlS at substantially the 'point where the extremities 62-63 merge'with `each other into the brace rod 64 (Figure 15). The Z lateral offset rodsr or struts 5&--59 serve as a counterpart. of a triangular rod 18 that extends from the verticalmedian position of the vertical brace rod 64 to the terminal socket bracket 5l of each leg unit 45-46. To this end, the terminal socketY bracket 5i has an intermediate socket 1,9 extending therefrom as at 8i! (Figure 1.1.5) f to -telescopically receive the lateral offset bracing rod 18 for welded joinder thereto as at 8 I It will be apparent, therefore, that each leg unit i5- 46y is reinforced both inthe plane thereof and laterally therefrom to comprise a self-contained rigid unit. t f

VThe terminal socket brackets 5I on each of the leg units 45-46, have an angularlyfoifsetfcastor supporting shaft 82 which extends at'the proper angle relatively to the angularity of the leg units 45'-46 to coincide with the linear pathof movement of the base frame 22 as will appear more fully` hereafter. A double-wheeled castor bracket or truck 83 is bored to receive the axle extension 84v of the' terminal bracket shaft 82 for retention thereon by any suitable means such asl aI fastener nut 85 which is in engagement with a threaded extremity 86 on Vthe terminalbracket axle 84.-y As a result, the terminal brackets 5I of the leg units 45-46 carry closely spaced doublewheels .8T-.88 mounted on stub shafts or axles V13T-83? to cooperate with the correspondingly sized. double-wheels itl-I9 journalled on the forward steering castor bracket l'I toserve as a mobile support for the base frame y22 'and the angularly disposed leg units 45-46.

In order to detachably connect the leg sections or units 45-45 to the base frame sections or units22, the upper angularly disposed rods 26 'of the base frame unit 22 extend beyond the vertical'struts 39--40 to provide tubular extensions respondingly'sized and shaped pins 9! extending thrcugh'the upper corner rod socketbrackets l54 The tubularrod extensions 89-90 on the base frame unit 22 telescopically receive the uper pins 9| extending from the top-corner rod bracket 54 on each of the leg'units l5-48; Onthe other hand, the lower angularly disposed rods 2l of the base frame unit 22extend beyond the vertical struts 39-40 to provide transversely disposed tubular bearings 92-93 which are adapted to confront correspondingly shaped and sized tubular bearings I94 integrally or otherwise attached to the lower corner rod socket brackets 53 of each of the leg units 45e-46. Spaced plates SI5-are apertured to correspondwith the bores in Y the'adjaeenuy disposed. tubular bearings s2-fs4 (Figure 13) and 93-94 so that a permanently connected pin 95 may extend therethrough to engage the tubular bearings 92--93 to afford the Y other pin or bolt 9'! may be detachably assocical column 98.

' 89-90 (Figure 9) serving as complements of cor- (Figure l0) ated with the space bracket to project through apertures thereof in alignment with the lower bearings 94 for projection therethrough in'detachably connecting leg units 45-46 to the base frame unit 22 against accidental separation. This enables the leg units 45-'46 to be detachably associated with the base frame unit 22 so that they may be readily assembled or dismantled depending upon the requirements of commercial practice or any particular usage. This provides a portable sub-structure of sectional con-y struction for any instrumentalities that may be advantageously supported therewith. f`

In the present embodiment, the 'superstrucl ture preferably though not essentially comprises a vertical column section 98 (Figures l and'lO). The vertical column 98 is, in this instance,v of

rtriangular cross-section to correspond with the triangular configuration of the section 26-28 30 of the base frame unit 22. To this end, three vertical struts `99,1#39 and I0! are disposed for yalignment with the vertical rods 25, 39 and 40 of the triangular section of the base frame 22 which are braced to conform therewith by means of triangularly arranged upper, intermediate, and lowerr angularly disposedk triangle forming rods |92, |92 and 03 corresponding with the diverging rods 26e-26 and 21-21 of the triangular sections of the base frame 22 deiined by y the upper and lower rods 2(5*29-30 and 21'- 21f-3l. l

In the present embodiment there are three sets of triangular lbraces 602, I02 and |03 that are interposed between the vertical corner rods 99, IDE) and IUI. These are connected to forward corner socket brackets H34 (Figures l and l0) and rearward corner socket brackets M35-H36 The rods IJZ-HBZ' and lil@ are welded or otherwise joined to corner rod sockets i04`i05l6 which are welded or otherwise 'anchored to the upper and lower extremities of the corner; rods 9=9-i and il deiining the verti1- Also intermediate the length of the Vertical corner rods 99, I9!! and IDI, the rod socket brackets |04', 05 and H36 are disposed to receive the vertical corner rods 99, EM and l0! therethrough. Suitable fastening expedients such as welding or the likemay be utilized to permanently join the corner brackets IML- and 106 to the vertical corner rods 99, i90-and I0! intermediate the length ythereof so that the superposed sets of triangularly disposed rods |02, |62' and ID3 will eiectively maintain the vertical corner rods 99, I and lili in properly-spaced relation. Thevertical column 98 is also braced by inclined struts I'l 'and m8 that are welded or otherwise joined between the corner brackets IIJ4-l5'and {U4-|06 (Figures l and'lO). In

tersecting'diagonal struts 09 are welded or otherwise joinedto the corner brackets M15-|99 and IGV-EBS to brace the upperrear plane of the vertical column defined by the upper portion of the corner rods HNL-HN. The lower half of the vertical column 98 is braced by intersecting diagonal struts H0, IH and H2 which areA interposed for welded joinder between the corner brackets -l0d-Hl5'-Hl'n", and the lower corner brackets HM, 185, HIS, respectively. In order that the vertical column may be more securely braced near the bottom St'thereof whereA the maximum -load would be sustained, horizontal brace .ro-ds ||3 and H4 are welded or otherwise secured to the forward corner rod 99 with their other eX- tremities terminating in the corner rods wil-I 5| as at IIE- l I, respectively, this being eifected after the brace rods 3-1 |4 are appropriately welded to the lower legs of the intersecting diagonal struts IIB-lll.

The vertical column 98 is detachably associated with the triangular section of the base frame 22 by telescopic association therewith. To this end, the forward corner rod 99 has a transverse tubular bearing I |1 to provide connection with space plates I|8 through the medium of a bolt H9. Another bolt |20 (Figure 1) engages -a corresponding tubular transverse bearing |2| (Figure 9) disposable adjacent to the transverse bearing ||1 (Figure 10) to effect locking engagement therebetween. The transverse tubular bearing |2| constitutes an extension of the corner bracket 28 to which the base frame vvertical rod 25 is welded, thereby enabling the detachable connection of the column 98 to the correspondingly shaped triangular section of the base frame 22. The vertical corner rods |00. and of the column 98, are provided with depending extensions |22-l23 (Figure l0) extending from the lower corner brackets IUS-|06, to telescopically .project within upstanding4 tubular extensions |24|25 constituting a part of the base frame vertical corner rods 39-40. This provides for the detachable association of column 98 in vertical linear alignment with the triangular section of the base frame 22, the lower extension |22|23 of the column 98 being retained in telescopic association with the tubular extension |24-I25 by the weight of column 98 together with whatever load will be sustained thereon as will appear more fully hereinafter. V

In order to sustain a boom in an angularly disposed position ior support on the vertical column 98, the forward column rod 99 thereof extends beyond'the upper corner bracket |04 to provide an upwardly directed extension |26 (Figures 1 and 7) terminating in a transverse tubular bearing |21 welded or otherwise attached thereto through its shank |28. The transverse Vbearing |21 is disposed between spaced plates |29| 30 which are bored to receive a pin 3| therethrough in alignment with the bore of the bearing |21. A cotter pin |32 may be utilized to retain the free extremity of the pin |31 against accidental Withdrawal from the bearing |21 and plates |29|30 (Figure 7). To the end of securing a boom |33 to the vertical column 98, a transverse tubular bearing |34 is disposed between the place plates IZB- |30 to receive another pin |35 therebe# tween after projecting through the tubular bearing |34 to effect the retention thereon which is assured by a cotter pin |36 projecting through 'l the free extremity of the pin |35.

The transverse tubular bearing |34 comprises, in this instance, a part of a triangular socket bracket |31 which forms the apex of a triangular frame dened by rods |38-,l39-l40 Rods |38-l39-I40 are welded or otherwise joined to the triangular apex socket bracket |31 while corner socket brackets' |4| and |42 receive the other extremities of the rods |38|39 for permanent connection thereto. It should be noted that the base rod |40 of the triangular boom frame |38|39|40 is, in this instance, of larger `diameter than the side rods |38|39 and correspond in diameter with the end brackets |4I-I42 for positioning therebetween (Figure 8). An elongated pintle pin |43 is axially disposed through the tubular rod |40 and bearings |4||42 to effect the retention of the boom |33 with its triangular base |38-I39-l40 in operative connection with the top extremity bearing |4|-|42 of the column 98. A'cotter pin |44 peripherally' projects through the extremity |45 to the pintle pin |43.

The boom |33 projects at an oblique angle to the column 98, and in the present embodiment comprises three elongated corner rods |46| 41- |48. The corner rods |46|41|48 are anchored at corresponding extremities to the corner socket brackets |31|4||42 to terminate in a socket bracket |49 (Figures 2 and 6) to which they are welded or otherwise joined to vdefine a boom of triangular configuration with the rod |46 appreciably longer than the rods |41|48 to prescribe the desired oblique angle of boom suspension relative to the vertical column 98. The tri-rod boom |33 is reinforced by angularly disposed brace rods |50|5| that extend from the corner socket brackets |4|| 42 to a sleeve |52 which envelops the boom rod |46 for welded joinder therewith and intersecting extremities of the brace rods |50-|5|. The tubular sleeve |52 also has triangular brace rods |54|55 extending therefrom in a direction opposite to the brace rods 50| 5 I, for welded joinder at their extremities |56-|51 t0 the rods |41-I48 proximate to the boom-end bracket |49. A transverse brace rod |58 extends between the juncture of the brace rod extremities |56|51 with the boom rods |41-|48. At these points of juncture another set of triangular brace rods |59|60 extend parallel to the brace rods |50|5| so that their intersecting extremities may be welded or otherwise joined as at |6| to the boom rod |46, thereby bracing the boom |33 along the entire length thereof.

To the end of providing hoisting instrumentalities, the extreme end of boom bracket |49 has a transverse tubular bearing |62 that serves to suspend space bracket plates |63|64 (Figures 2 and 6). The space plates |63| 64 are rigidly joined to the transverse bearing |62 to depend therefrom to effectively support a transverse stub shaft |65 that extends therebetween for connec- H tion through the medium of nut fasteners |66-i61 in threaded engagement with the extremities of the stub shaft |65 (Figure 2). A sheave |68 is journalled on the stub shaft |65, it being provided with a grooved periphery |69 to carry a tension cable |10 thereover. The tension cable |10 terminates in a hook |1| which serves to engage the exible loop or other expedient for either enveloping a device that is to be lifted therewith or otherwise attached thereto unless such devices or parts to lbe lifted with the hook |1| have complemental fastening expedient for engagement therewith.

The tension cable |10 extends between the boom rods |46--I41-l48 for guidance over an idler sheave |12 which is mounted for journaled rotation on a bracket |13 attached to the sleeve |04 which is welded or otherwise joined as described supra to the column rod 99. The bracket |13 corresponds substantially with the bracket plates |63-|64 (Figure 2), and these are attached to the sleeve |04, similar to the mode of attachment of the plates |63-|64 to the bearing |62. The idler sheave |62 guides the tension cable |10 thereover to extend vertically downwardly within the column 98 for operative connection and convolute winding over the drum |14 of a winch |15 of suitable or standard construction. In the present embodiment the winch 15 is manually operated by a handle |16 although other sources of power may be utilized depending upon the dictates of commercial practice. The

winch is bolted as at I11|18 (Figure 1) to anglebrackets |19-I80 and |8| Welded or otherwise permanently joined tothe angularly disposed rods 26-26 of thetriangular section of the base frame-22 (Figure 9)'. y

yWith this yarrangemenathe hook |1 may be detached from the cable |10 which-is wound on the `winch drum |14 Whenever itis desired to separate the base frame 22 from the column 98, and the boom |33 from the latter. To accomplish this end it is only necessary to remove a pin |35 from between the plates |29-l30, and Withdraw the pintle pin |43 from the sleeve rod |40 and the brackets I4 I-|42, thereby enabling the boom |33 to be lifted or detached therefrom. The column 98 is similarly detached from the frame 22 by removing one or the other of the bolts IIS-|20, and both of the legs 45--46 are detachable from the frame 22 by removing the pin or bolt 96 or 91 from each of the transverse bearings 92,-93 of the base frame 22 (Figure 9).' This accounts for the complete dismantling of the entire structural unit so that they may be conveniently carried in aircraft or other vehicles from one point to another Wherever. required for servicing and maintenance. A light,l Strong, and comparatively inexpensive portable hoist has thus been provided which is primarily adaptable for maintenancev and replacement of essential parts of aircraft such as engines, Wings, under-carriage, and similar majorparts that are much too heavy for lmanual lifting into position.

Various changes maybe made in the embodiment of the invention herein specifically ldescribed without departing from or sacrificing any of the advantages of the invention or any features thereof, and nothing herein shall be construed as limitations 'upon the invention, its concept or structural embodiment as to-the Whole or any part thereof except as dened in the appended claims.

, Iclaim:r

l. In a device of the character described,lthe combination with a plurality of complemental truss-rod three-dimensional strut sections including angularly related leg units to define a frame, means for detachably associating said frame sections, a truss-rod column sectiondetachably associated With said frame, hoist meansv associated with said column and frame, and means for locking said detachable franuie section and column against accidental displacement.

2, In a portable sectional device of the character described, the combination with a plurality of complemental truss-rod three-dimensional strut sections comprising detachable associated selfsustaining base, leg, column and boom units, of Wheel mounted castor trucks on said base and leg units to serve as a movable support for all of said units, one of said Wheel mounted castor trucks being pivotally connected to said base, means for detachably associating said leg units f with said base unit, a handle attached to said pivotally connected castor truck to enable the steeringthereof, means for detachably connecting said units against accidental separation, and hoist means associated with certain of said units.

3. In av portable hoist device of the character described, the combination with a plurality of complemental three-dimensioned strut sections comprising self-sustaining truss-rod, base, leg, column and boom units of substantially triangular cross-section, of Wheel mounted castor trucks on said base and leg units to serve as a support therefor, means for detachably associating said units, means for readily connecting said units truss-rod three-dimensional strut sections com- ,y

prising detachably `associated self-sustaining base, column, boom and angularly spaced leg units, said units being of substantially triangular l cross-,sectionalconfiguration, of Wheel Amounted castor trucks `on said -base and legunits to serve asa support therefor, means for detachably connecting said units against accidental separation, said column unit being vertically associated With said base, said boom unit being angularly4 associated with said column, and said leg units being angularly associated With said base.

5. Ina device of the character described, the combination with a plurality of complemental three-dimensional strut units including spaced leg units and a base unit detachably connected to define a frame, of Wheel mounted castor trucks on said frame units to serve as a support therefor, means for detachably connecting said frame units against accidental separation, a column unit detachably associated with said frame units, an angularly disposed `boom unit detachably associated with said column unit, said units being of tubular rodconstruction having triangular crosssectional configurations, and hoist means associated With said boom, column and frame units.

6. In a portable sectional device of the character described, the combination with a plurality of complemental three dimensional strut units including a base and angularly spaced leg units to define a frame, of wheel mounted castor trucks on said frame to serve as a support therefor, one of said wheel mounted trucks being pivotally connected to said frame to enable the steering thereof, means for detachably connecting said base and leg units to define a sectional framefa vertical unit detachably associated with said frame, an angularly disposed boom unit detachably associated with said column unit, said units being of truss-rod triangular construction to ren-y der each self-sustaining, and hoist means associated with said boom, column and frame.

7. In a device of the character described, the combination with a plurality of complemental three-dimensional strut units including a base and angularly spaced leg units to define a frame, of Wheel mounted castor trucks on said frame to serve as a support therefor, one offsaid wheel mounted trucks being pivotally connected to said frame, a handle attached to said pivotally connected castor trucks to enable the steering movement thereof, means for detachably connecting said base and leg units to define a sectional frame, a vertical unit detachably associated with said frame, a lboom unit detachablyassociated 'with said column unit, means for locking said units together against accidental separation, said units being of truss-rod triangular construction to renconfiguration, hoist means associated with said column and base units, and means for locking render such portable, one of said wheeled mount- 10 ing trucks' being pivotally connected to a forward portion of said base punit,l a handle operatively connected' to said pivotally' connected wheeled truck for pulling and steering purposes, a trussrod column unit detachably associated 'with said base' unit,- hoistl means associated' with said co1- umn and base units, and means for locking said detachable units against' accidental separation.

CHARLES E. WATSON. 

